Incredible idea, and I love the execution! <3 Simple and effective!
I do want to take note of how flimsy your "flow" graph is (Skill needed / difficulty ratio per level over time), with a VIOLENT thrust upwards mid-way and then a violent thrust downwards near the end. Level design is a key in a game like this, so watch out!
And you know what would be interesting and immediately make the game super replayable? A Par system and a level select, maybe a few medals for doing so. As a huge flash game fan, this seems like one amazing one ready to be put on some sites out there. Really well done - probably one of my faves of the jam!